1 Setting up data

Data from Human Mortality Database and Human Fertility Database was used to calculate birth rates. This was tidied to give Under-18 rates:

Code Country Year rate GDPperCap MF_ratio MobilePhones UrbanPop
5 Denmark 1990 2.94 26891.44 1.04 2.88 84.84
5 Denmark 1991 2.65 27011.39 1.04 3.41 84.87
5 Denmark 1992 3.08 29569.65 1.04 4.08 84.90
5 Denmark 1993 2.90 27597.97 1.04 6.89 84.92
5 Denmark 1994 2.71 29995.57 1.05 9.66 84.95
5 Denmark 1995 2.19 35351.38 1.05 15.71 84.98

Abortion estimates were added to give Under-20 rates:

Code Country Year pRate rate GDPperCap MF_ratio MobilePhones UrbanPop
4 Denmark 1990 26.51 9.20 26891.44 1.05 2.88 84.84
4 Denmark 1991 25.33 9.00 27011.39 1.04 3.41 84.87
4 Denmark 1992 25.43 9.70 29569.65 1.04 4.08 84.90
4 Denmark 1993 24.81 9.14 27597.97 1.05 6.89 84.92
4 Denmark 1994 24.07 9.21 29995.57 1.05 9.66 84.95
4 Denmark 1995 23.08 8.72 35351.38 1.05 15.71 84.98

1.1 Removing non-fitting countries

Several countries were removed (detail added later).

2 Iterating through year combinations

For each comparison, I iterated through all combinations of years as special predictors to minimise MSPE (whilst prioritising fewest groupings). For example, for the under-18 basic model with years as special predictors:

it_u18_sp <- testSynthIterations(
  yrs = 1990:1998,
  pred = "rate",
  data = synthData_u18[,1:4],
  ccodes = u_18_ccodes,
  n = 4,
  predictors = NULL,
  time.optimise = 1985:1998
) %>%
  arrange(groups, mspe)

3 All countries, no additional predictors

3.1 Model 1: Under-18 birth rates

3.1.1 All Countries graph

3.1.2 England vs Synthetic Control

Over the period 1999 to 2013, England and Wales saw a difference of -3,744 births (to an average population of 995,340 women).

3.1.3 Weights and balance

Country weights
Country Weight
Scotland 0.672
Portugal 0.295
United States of America 0.016
New Zealand 0.012
Iceland 0.001
Sweden 0.001
Switzerland 0.000
Germany 0.000
Denmark 0.000
Spain 0.000
Finland 0.000
France 0.000
Italy 0.000
Netherlands 0.000
Norway 0.000
Predictor weights
v.weights
special.rate.1990.1993 0.01
special.rate.1994 0.333
special.rate.1995 0.295
special.rate.1996.1998 0.362
Predictor balance between synthetic and treated units
Treated Synthetic Sample Mean
special.rate.1990.1993 16.214 16.275 10.415
special.rate.1994 15.078 14.952 9.629
special.rate.1995 15.285 15.561 9.660
special.rate.1996.1998 16.836 16.728 9.257

3.1.4 Placebo testing by country and time

In placebo-country tests, England and Wales ranked 14 out of 16 countries by pre/post-MSPE ratio.

3.2 Model 2: Under-20 pregnancy rates

3.2.1 All Countries graph

3.2.2 England vs Synthetic Control

Over the period 1999 to 2013, England and Wales saw a difference of 152,471 pregnancies (to an average population of 1,668,190 women).

3.2.3 Weights and balance

Country weights
Country Weight
Scotland 0.639
United States of America 0.227
Iceland 0.134
Switzerland 0.000
Germany 0.000
Denmark 0.000
Spain 0.000
Finland 0.000
France 0.000
Italy 0.000
Netherlands 0.000
Norway 0.000
Portugal 0.000
New Zealand 0.000
Sweden 0.000
Predictor weights
v.weights
special.pRate.1990 0.152
special.pRate.1991.1995 0.578
special.pRate.1996.1998 0.271
Predictor balance between synthetic and treated units
Treated Synthetic Sample Mean
special.pRate.1990 68.000 65.337 35.661
special.pRate.1991.1995 60.620 62.055 32.224
special.pRate.1996.1998 63.633 61.259 30.895

3.2.4 Placebo testing by country and time

In placebo-country tests, England and Wales ranked 11 out of 16 countries by pre/post-MSPE ratio.

4 Filtered to remove Scotland, no additional predictors

4.1 Model 3: Under-18 birth rates

4.1.1 England vs Synthetic Control

Over the period 1999 to 2013, England and Wales saw a difference of -17,765 births (to an average population of 995,340 women).

Loss-V (For optimised period) = 0.616, MSPE (for whole pre-intervention observation period) = 0.616.

4.1.2 Weights and balance

Country weights
Country Weight
Portugal 0.807
New Zealand 0.193
Switzerland 0.000
Germany 0.000
Denmark 0.000
Spain 0.000
Finland 0.000
France 0.000
Iceland 0.000
Italy 0.000
Netherlands 0.000
Norway 0.000
Sweden 0.000
United States of America 0.000
Predictor weights
v.weights
special.rate.1990.1993 0.206
special.rate.1994 0.156
special.rate.1995 0.318
special.rate.1996.1998 0.32
Predictor balance between synthetic and treated units
Treated Synthetic Sample Mean
special.rate.1990.1993 16.214 16.587 9.928
special.rate.1994 15.078 15.963 9.210
special.rate.1995 15.285 15.782 9.155
special.rate.1996.1998 16.836 15.803 8.607

4.1.3 Placebo testing by country and time

In placebo-country tests, England and Wales ranked 14 out of 16 countries by pre/post-MSPE ratio.

4.2 Model 4: Under-20 pregnancy rates

4.2.1 England vs Synthetic Control

Over the period 1999 to 2013, England and Wales saw a difference of 250,707 pregnancies (to an average population of 1,668,190 women).

Loss-V (For optimised period) = 6.03, MSPE (for whole pre-intervention observation period) = 6.03.

4.2.2 Weights and balance

Country weights
Country Weight
Iceland 0.359
United States of America 0.353
New Zealand 0.288
Switzerland 0.000
Germany 0.000
Denmark 0.000
Spain 0.000
Finland 0.000
France 0.000
Italy 0.000
Netherlands 0.000
Norway 0.000
Portugal 0.000
Sweden 0.000
Predictor weights
v.weights
special.pRate.1990 0.309
special.pRate.1991.1995 0.498
special.pRate.1996.1998 0.193
Predictor balance between synthetic and treated units
Treated Synthetic Sample Mean
special.pRate.1990 68.000 67.005 34.180
special.pRate.1991.1995 60.620 62.152 30.590
special.pRate.1996.1998 63.633 60.236 28.987

4.2.3 Placebo testing by country and time

In placebo-country tests, England and Wales ranked 9 out of 15 countries by pre/post-MSPE ratio.

5 Adding all predictors

5.1 Model 5: Under-18 birth rates

5.1.1 England vs Synthetic Control

Loss-V (For optimised period) = 2.5, MSPE (for whole pre-intervention observation period) = 2.5.

5.1.2 Weights and balance

Country weights
Country Weight
Italy 0.374
Iceland 0.328
United States of America 0.298
Switzerland 0.000
Germany 0.000
Denmark 0.000
Spain 0.000
Finland 0.000
France 0.000
Netherlands 0.000
Norway 0.000
Portugal 0.000
Sweden 0.000
Predictor weights
v.weights
special.rate.1990.1993 0.028
special.rate.1994 0.023
special.rate.1995 0.034
special.rate.1996.1998 0.15
special.GDPperCap.1990.2003 0.014
special.GDPperCap.2004 0.078
special.GDPperCap.2005.2010 0.014
special.GDPperCap.2011.2013 0.002
special.edu_spend.1995.1998 0.003
special.edu_spend.1999.2007 0
special.edu_spend.2008.2013 0.13
special.MobilePhones.1990.1992 0
special.MobilePhones.1993.1995 0.022
special.MobilePhones.1996.1997 0.011
special.MobilePhones.1998.2013 0.126
special.UrbanPop.1990 0.092
special.UrbanPop.1991 0.088
special.UrbanPop.1992 0.087
special.UrbanPop.1993.2013 0.098
Predictor balance between synthetic and treated units
Treated Synthetic Sample Mean
special.rate.1990.1993 16.214 17.099 8.005
special.rate.1994 15.078 16.268 7.329
special.rate.1995 15.285 16.157 7.099
special.rate.1996.1998 16.836 14.511 6.703
special.GDPperCap.1990.2003 24800.333 26808.216 26870.008
special.GDPperCap.2004 39983.985 39557.010 39108.220
special.GDPperCap.2005.2010 43340.344 44960.799 47573.339
special.GDPperCap.2011.2013 41975.732 43998.534 52420.115
special.edu_spend.1995.1998 4.223 5.330 5.616
special.edu_spend.1999.2007 5.296 5.885 5.627
special.edu_spend.2008.2013 5.794 5.884 5.691
special.MobilePhones.1990.1992 2.256 2.896 2.778
special.MobilePhones.1993.1995 6.881 7.278 7.214
special.MobilePhones.1996.1997 13.808 18.177 18.310
special.MobilePhones.1998.2013 98.113 95.733 93.736
special.UrbanPop.1990 78.140 77.151 74.238
special.UrbanPop.1991 78.112 77.323 74.478
special.UrbanPop.1992 78.172 77.514 74.734
special.UrbanPop.1993.2013 79.690 79.327 77.582

5.1.3 Placebo testing by country

In placebo-country tests, England and Wales ranked 5 out of 14 countries by pre/post-MSPE ratio.

5.2 Model 6: Under-20 pregnancy rates

5.2.1 England vs Synthetic Control

Loss-V (For optimised period) = 17.2, MSPE (for whole pre-intervention observation period) = 17.2.

5.2.2 Weights and balance

Country weights
Country Weight
United States of America 0.522
Iceland 0.278
Italy 0.201
Switzerland 0.000
Germany 0.000
Denmark 0.000
Spain 0.000
Finland 0.000
France 0.000
Netherlands 0.000
Norway 0.000
Portugal 0.000
Sweden 0.000
Predictor weights
v.weights
special.pRate.1990 0.175
special.pRate.1991.1995 0.156
special.pRate.1996.1998 0.315
special.MobilePhones.1990.1992 0
special.MobilePhones.1993.1995 0.001
special.MobilePhones.1996.1997 0.004
special.MobilePhones.1998.2013 0.054
special.edu_spend.1995.1998 0
special.edu_spend.1999.2007 0
special.edu_spend.2008.2013 0.001
special.GDPperCap.1990.2003 0
special.GDPperCap.2004 0.014
special.GDPperCap.2005.2010 0
special.GDPperCap.2011.2013 0.006
special.UrbanPop.1990 0.11
special.UrbanPop.1991 0.087
special.UrbanPop.1992 0.071
special.UrbanPop.1993.2013 0.004
Predictor balance between synthetic and treated units
Treated Synthetic Sample Mean
special.pRate.1990 68.000 68.849 32.961
special.pRate.1991.1995 60.620 63.155 29.104
special.pRate.1996.1998 63.633 57.510 27.083
special.MobilePhones.1990.1992 2.256 3.182 2.778
special.MobilePhones.1993.1995 6.881 8.184 7.214
special.MobilePhones.1996.1997 13.808 18.494 18.310
special.MobilePhones.1998.2013 98.113 85.702 93.736
special.edu_spend.1995.1998 4.223 5.570 5.616
special.edu_spend.1999.2007 5.296 6.133 5.627
special.edu_spend.2008.2013 5.794 6.239 5.691
special.GDPperCap.1990.2003 24800.333 28604.113 26870.008
special.GDPperCap.2004 39983.985 41170.217 39108.220
special.GDPperCap.2005.2010 43340.344 46569.676 47573.339
special.GDPperCap.2011.2013 41975.732 46884.569 52420.115
special.UrbanPop.1990 78.140 77.870 74.238
special.UrbanPop.1991 78.112 78.125 74.478
special.UrbanPop.1992 78.172 78.389 74.734
special.UrbanPop.1993.2013 79.690 80.692 77.582

5.2.3 Placebo testing by country

In placebo-country tests, England and Wales ranked 8 out of 14 countries by pre/post-MSPE ratio.